There are great demands for a device that detects or measures vibratory movements of small amplitudes between two objects in a simple and accurate manner which device has a small bulk and light weight and its function is immune to the ambient noises such as electromagnetic fields. One area of particular interest in the application of the vibratory motion sensor is the vibrating conduit mass flowmeters, which devices are commonly known as the "convective inertia force flowmeter" or the "Coriolis force flowmeter". At the present time, motion sensors of magnetic induction coil types are employed without any exception in the construction of the vibrating conduit mass flowmeters. Another important area of application of the vibratory motion sensor is the vibrating conduit density meters, which determine the density of fluid contained in the conduit from one or more natural frequencies of the flexural vibration of the conduit. In general, vibrations in all types of industrial and commercial machineries are highly dangerous and destructive phenomena, which require an accurate and reliable monitoring wherein a better vibratory motion sensor can greatly improve the safety and economics in the operation of those machineries.